Abstract2_1 (Hasumi)

Hasumi, M., and H. Iwasawa: Geographic variation in morphological characters of the Japanese salamander, Hynobius lichenatus. Science Reports of Niigata University, Series D (Biology) 24: 15-30, March 1987.

Abstract: During the breeding seasons of 1983-1985, 283 males and 49 females of adult Hynobius lichenatus were collected from 19 localities in northeastern Japan. Digits of adpressed limbs overlapped one to two costal folds in males, whereas they either met or were separated by one fold in females. The number of costal grooves between the axilla and groin, omitting the axillary groove, was 10 to 12, modal number being 11. Individuals from 4 localities in Aomori Prefecture had only 11 costal grooves. However, the relative frequency of 12 costal grooves was much higher in some localities. Intra- and interpopulation variations were found in the degree of development of the 5th toe of the hindlimb. Many specimens tended to have well developed 5th toes in the populations from areas on the Japan Sea side, but only some on the Pacific Ocean side. A significant positive correlation was found between the mean snout-vent length and the degree of development of the 5th toe, except for one population in Iwate Prefecture in which most specimens had poor 5th toes in spite of their larger body size. That is, the high occurrence of poor 5th toes in some localities was correlated with the smaller body size as a population. Thus, external features that have been attributed to the taxonomic characters in this species are not stable.